The aim of the study was to analyze the clinical use of different types of combination therapy in a large sample of consecutive patients with uncontrolled hypertension referred to Hypertension Centre. We performed a retrospective analysis of combination antihypertensive therapy in 1254 consecutive patients with uncontrolled hypertension receiving at least triple-combination antihypertensive therapy. Among the most prescribed antihypertensive classes were renin-angiotensin blockers (96.8%), calcium channel blockers (82.5%), diuretics (82.0%), beta-blockers (73.0%), centrally acting drugs (56.0%) and urapidil (24.1%). Least prescribed were spironolactone (22.2%) and alpha-1-blockers (17.1%). Thiazide/thiazide-like diuretics were underdosed in more than two-thirds of patients. Furosemide was prescribed in 14.3% of patients treated with diuretics, while only indicated in 3.9%. Inappropriate combination therapy was found in 40.4% of patients. Controversial dual and higher blockade of renin-angiotensin system occurred in 25.2%. Incorrect use of a combination of two antihypertensive drugs with the similar mechanism of action was found in 28.1%, most commonly a combination of two drugs with central mechanism (13.5%). In conclusion, use of controversial or incorrect combinations of drugs in uncontrolled hypertension is common. Diuretics are frequently underdosed and spironolactone remains neglected in general practice. The improper combination of antihypertensive drugs may contribute to uncontrolled hypertension.